Methods of controlling insects or nematodes by using s,s-substituted 2,2-thio-,sulfinyl-,and sulfonyl-alkanyl and alkanone n-substituted carbamoyloximes and their carbonyl derivatives

ABSTRACT

METHODS OF CONTROLLING INSECTS, ACARIDS AND NEMATODES BY APPLYING TO PLANTS OR TO THE SOIL IN WHICH THEY ARE GROWING S,S-SUBSTITUTED THIO-, SULFINYL-, SULFONYL- ALKANAL AND -ALKANONE N-SUBSTITUTED CARBAMOXYLOXIME DERIVATIVES.

United States Patent METHODS OF CONTROLLING INSECTS 0R NEMA- TODES BYUSING S,S-SUBSTITUTED 2,2-THIO-, SULFINYL, AND SULFONYL-ALKANYL ANDALKANONE N-SUBSTITUTED CARBAMOYLOX- IMES AND THEIR CARBONYL DERIVATIVESTomas L. Fridinger and Edward L. Mutsch, Woodbury Township, WashingtonCounty, Minn., assignors to Minnesota Mining and Manufacturing Company,St. Paul, Minn.

No Drawing. Application July 11, 1969, Ser. No. 841,142, now Patent No.3,646,062, dated Feb. 29, 1972, which is a continuation of abandonedapplication Ser. No. 753,752, Aug. 19, 1968. Divided and thisapplication Feb. 9, 1972, Ser. No. 224,955

Int. Cl. A01n 9/00, 9/12 US. Cl. 424-277 4 Claims ABSTRACT OF THEDISCLOSURE Methods of controlling insects, acarids and nematodes byapplying to plants or to the soil in which they are growingS,S-substituted thio-, sulfinyl-, sulfonylalkanal and -alkanoneN-substituted carbamoxyloxime derivatives.

This is a division of application Ser. No. 841,142 filed July 11, 1969,now US. Patent 3,646,062 issued Feb. 29, 1972, which is a continuationof Ser. No. 753,752, filed Aug. 19, 1968, now abandoned.

Certain alkanal and alkanone oxime carbamates are known to the art whichpossess insecticidal, miticidal or nematocidal activity, for example seeUS. Patents 3,299,- 137 and 3,217,037. However, compounds in which onealpha carbon atom of the alkanal or alkanone portion of an oxime isbonded to two substituted sulfur atoms, or their carbamate derivatives,have not been previously reported nor has the use of the latter aseffective insecticides, acaricides and nematocides been suggested.

This invention relates to S,S-substituted 2,2-thio-, sulfinylandsulfonyl-alkanal and -al kanone oximes and their N-substitutedcarbamoyloxime derivatives. These novel carbamoyloxime derivativespossess insecticidal, acaricidal and nematocidal activity.

The present invention provides compounds of the formula BIA! R3 RZAZ/(IJ=NOH R4 and their carbamoyloxime derivatives of the formula RlA-l RaQ=NOCN\ it, ('i R,

wherein A and A are independently selected from the group consisting ofthio, sulfinyl and sulfonyl linkages, R R and R are independentlyselected from the group consisting of alkyl and alkenyl having up to 4carbon atoms, or R and R taken together form an alkylene or alkenylenegroup having up to 12 carbon atoms, having 2 to 5 carbon atoms in thechain linking the sulfur atoms, R., is hydrogen or alkyl having up to 4carbon atoms, and R and R are independently selected from the groupconsisting of hydrogen and alkyl, cycloaliphatic, alkoxy and alkenylradicals having up to about 10 carbon atoms, and only one of R and R maybe hydrogen.

In the presently preferred compounds of the present invention R ismethyl or ethyl, R and R together either 3,720,772 Patented Mar. 13,1973 contain no more than 5 carbon atoms or form an alkylene linkinggroup having 2 or 3 carbon atoms in the chain linking the sulfur atoms.R, is hydrogen, R is methyl or ethyl and R is hydrogen. Such compoundsare preferred because they exhibit a superior degree of nematocidalactivity although all of the compounds disclosed herein have a degree ofnematocidal action.

The oxime compounds used as starting materials in both of the abovedescribed alternative synthetic procedures may be prepared from thecorresponding aldehydes or ketones by reaction with hydroxylaminehydrochloride in the presence of an acid acceptor such as potassiumacetate in a suitable solvent such as ethanol.

Some exemplary oxirnes are the following:

S on.

5-formyl-5-methyl4, 5-dlthiepin oxime CHzhCH;

2-fqrmyl-2-(n-butyl)-4-ethyl-1, 3-d1tl1lolane oxime tetraoxide2-formyl-2, B-dlmethyl-l, 3- dithiaue oxime monoxide CH=NOH The aldehydeand ketone precursors used to prepare useful oximes ma, be prepared bymethods known to the art, e.g. the reaction of alpha-ketoaldehydes withmercaptans as described by Tomas L. Fridinger, Ph.D. Thesis, Universityof Maryland, 1967 (it has been discovered that this reaction may also beapplied to alpha-diketones), or the formylation or alkanoylation ofdithio-substituted carbon atoms in the presence of very strong bases, asde scribed by E. J. Corey et al., Angewandte Chemie, InternationalEdition, 4, 1075 (1965).

When the reaction of alpha-ketoaldehydes with mercaptans is applied tosymmetrical alpha-diketones, only one isomeric ketomercaptol ispossible. When this reaction is applied to unsymmetricalalpha-diketones, isomeric mixtures of ketomercaptols are obtained whichmust be separated.

The carbamoyloxime compounds of this invention can be prepared in avariety of ways from the correspondingly substituted oximes. Onesynthetic route involves addition of an isocyanate to the substitutedoxime having R R R and R substituents corresponding to the desiredcompound and is illustrated by the following equation wherein A A R R RR and R are defined as before:

R1 1 I h 1 12 The isocyanate addition can be carried out, generally, bycontacting the oxime with the isocyanate in an inert organic solvent,and preferably in the presence of a tertiary amine as a catalyst. Thereaction may be effected at temperatures ranging from about C. to about130 C. and is preferably carried out between room temperature and 80 C.Generally, temperatures substantially in excess of about 130 C. are tobe avoided in view of the temperature sensitivity of the productcarbamoyloxime. The operating pressure may range from about 1 atmosphereto about 10 atmospheres, preferably from about 1 to about 3 atmospheres,and is dependent upon the concentration and vapor pressure of thevolatile isocyanate at the reaction temperature. The inert organicsolvents that can be employed in the reaction are those inert toisocyanates in general, i.e., those free of radicals such as hydroxy oramino radicals. Illustrative solvents are aliphatic ketones such asacetone, aliphatic and aromatic hydrocarbons, such as hexane, heptane,octane, benzene, toluene and the like. Generally, amounts of saidtertiary amine catalyst from about 0.1 to about 1.0 weight percent ofthe starting material comprised of an isocyanate and the oxime aresufiicient. Aliphatic and/or aromatic tertiary amines are useful forthis purpose, e.g. dimethylaniline, triethylamine or the like. The moleratio of isocyanate to oxime can range from about 0.25:1 to about 2:1,but preferably an equimolar amount or slight excess of the isocyanate isemployed to insure that the oxime is completely reacted. The reactiontime may vary from about 5 minutes to about 7 days, but normally whenoperating in the preferred temperature range, reaction times of fromabout one-half hour to about 5 hours are sufficient for completereaction.

The carbamoyloxime product formed, either a solid or oily liquid, can berecovered from the reaction mixture by means known to the art, eg byvacuum-distillation to drive off solvent and excess isocyanate.

Another synthetic route involves the reaction of a substituted oximewith phosgene to form the chloroformate which in turn is reacted with acompound containing a reactive amino function such as a primary orsecondary amine, substituted h'ydroxylamines and the like to give thedesired oxime carbamate of this invention. The synthesis is illustratedby the following equations wherein A A R R R R R and R are defined asbefore:

In step (1) above, a solution of the oxime compound in e.g. ethyl etheris conveniently added slowly to a solution of phosgene in toluene orethyl ether or other suitable organic solvent in the presence of ahydrochloric acid acceptor such as a suitable amine, e.g. dimethylaniline. The reaction can be carried out at from 30 C. to about 40 C.,but will generally be found to proceed most advantageously between 10 C.and room temperature. The reaction is slightly exothermic so that someexternal cooling is usually necessary to maintain the temperature withinthe desired range. The reaction mixture can be washed with water toremove the byproduct amine hydrochloride and the organic layercontaining the chloroformate (IV) can be used for further reactions. Theaddition of the reactant containing a reactive amino function, step (2)above, is carried out in the presence of solvents for said reactant,such as water, dioxane, toluene or chloroform, at temperatures betweenabout 40 C. and about C. and preferably below about 40 C. inasmuch asthe reaction proceeds smoothly even at low temperatures and is so rapidabove 40 C. that loss of low boiling reactants may occur and somedeomposition may take place.

The sulfinyland sulfonyl-linked compounds of our invention are preparedby oxidizing the corresponding sulfide-linked carbamoyloxime compound ofthe invention with dilute solutions of peracetic acid or with sodiummetaperiodate. Alternatively, the oxidation step may be carried outusing the alkanal, alkanone or oxime interme diates, using selectiveconditions known to the art. It may be desirable, or even necessary, toprotect the carbonyl group before oxidation, for example by forming theacetal or ketal.

The invention will be further understood by reference to the followingillustrative and non-limiting examples, in which all parts are by weightunless otherwise noted. All melting points given are uncorrected.

EXAMPLE 1 agar-Bis (methylthio)propionaldehyde oxime N-methylcarbamateN,N,N,N'-tetramethylethylenediamine (11.6 g., 0.1 mole) is added to 71.5ml. of 1.4 N n-butyllithium in hexane at -20 C. Acetaldehydedimethyldithioacetal.

(12.2 g., 0.1 mole) is added dropwise to this mixture. After 2 hours,8.05 g. of dimethylformamide (0.11 mole) is added dropwise. The reactionis allowed to warm to room temperature and stirred overnight. Themixture is poured into 200 ml. of water, acidified and extracted with 75ml. of hexane three times. The combined extracts are washed with ml. of2 percent potassium hydroxide and 50 ml. of water two times, dried overmagnesium sulfate and evaporated in vacuo. The residue weighs 9.95 g.The infrared spectrum of the product is consistent with the assignedstructure for a,a-bis(methylthio)propionaldehyde.

or, Bis(methylthio)propionaldehyde (9.95 g., 55 mmoles), potassiumacetate (6.47 g., 66 mmoles) and hydroxylamine hydrochloride (4.58 g.,66 mmoles) are refluxed 3 hours in 80 ml. of ethanol. Potassium chlorideis removed by filtration and the filtrate evaporated to near dryness.The addition of ice precipitates a cream solid which is collected byfiltration. The infrared spectrum is consistent with the assignedstructure for oc,ot-biS(1I16thYlthio)propionaldehyde oxime.

Four drops of triethylamine and 3.8 g. ofa,u-bis(methylthio)propionaldehyde oxime (23 mmoles) are dissolved in 30ml. of chloroform. Methyl isocyanate (5.24 g., 92 mmoles) in 10 ml. ofchloroform is added dropwise, with stirring. The mixture is heated toreflux, refluxed for two hours and then evaporated in vacuo. Theresidual oil is triturated with a 50/50 mixture of hexane and benzene.This solid is recrystallized from 50/50 hexane/benzene, and the producthas a melting point of 62-65 C. Its infrared and proton magneticresonance spectra are consistent with the assigned structure of thedesired carbamoyloxime compound.

Analysis.Calculated for C7H14N202S2 (percent): C, 37.8; H, 6.3; N, 12.6.Found (percent): C, 38.1; H, 6.1; N, 12.4.

Using the procedure of Example 1 the products of the following table areobtained using commercially available isocyanates as the reactants.

TABLE I Reaetants Example No. Oxime Isoeyanate Product 2a,a-Bis(methy1thio)propionaldehyde oxime.-." n-Butylisocyanatea,a-%is(mfithylthio)propionaldehyde oxime N-n-butyl- 081 81118. e. i.do- Allylisocyanate egg-Bisgmethylthio)propionaldehyde oximeN-allylcar- 31113. 0. 4 .do..- Ethyl isocyanateegg-Bisgmethylthio)propionaldehyde oxime N-ethylear- 11119. 9. a doCyelohexyl isocyanate a,a-Bis(methylthio)propionaldehyde oximeN-cyclohexylcarbamate.

2-formyl-2,5-dimethylbenzo-1,3-dithiolane oxime, EXAMPLE 62-formyl-2-methyl-4-phenyl-1,3-dithiolane oxime, 2-formyl-2-methy OXlme-d1- 2-formyl-2,4-dimethyl-1,3-dithiane oxime,

methylcarbamate 4-ethyl-2-formyl-2-methyl-1,3-dithiolane oxime,

A stirred mixture of 360.3 g. of a 40 percent aqueout solution ofpyruvaldehyde (2.0 moles), 179 g. of 1,2-ethanedithiol (1.90 moles), 600ml. of benzene and 2.0 g. of p-toluenesulfonic acid hydrate is heated atreflux for 4 hours, during which time about 175 ml. of water separatesin a Dean-Stark trap. The dark brown solution is stirred for 6 hours atroom temperature, then poured into 300 ml. of diethyl ether. Thissolution is washed with 500 ml. of 5 percent sodium bicarbonatesolution, then 500 ml. of water, and dried over magnesium sulfate. Thedried solution is fractionally distilled under water pump vacuum, andthe fraction boiling from 105 to 108 C. is examined by infraredanalysis. The spectrum of the fraction is consistent for the structureof 2-formyl- 2-methyl-l,3-dithiolane.

Analysis.Calculated for C H OS (percent): C, 40.5; H, 5.4. Found(percent): C, 40.7; H, 5.6.

Using the general method described, the following derivatives ofa-dicarbonyl compounds useful as intermediates for the preparation ofoxime intermediates of the present invention are prepared from knownstarting materials. These intermediates are identified by their methodof synthesis and infrared spectra.

2-formyl-Z-methylcyclohexano-1,3-dithiolane,2-formyl-2,4,6-trimethyl-1,3-dithiane, 2-formyl-2-methyl-1,3-dithiane,2-formyl-2,4-dimethyl-1,3-dithiolane,2-formyl-2,S-dimethylbenzo-1,3-dithiolane,2-formyl-2-methyl-4-phenyl-1,3-dithiolane,2-formyl-2,4-dimethyl-1,3-dithiane,4-ethyl-2-formyl-2-methyl-1,3-dithiolane,2-acetyl-2-methyl-l,3-dithiolane, 2-acetyl-2,4-dimethyl-1,3-dithiolane,and 2-ethyl-2-propionyl-1,3-dithiolane.

A stirred mixture of 162.4 g. of 2-formyl-2-methyl-l,3- dithiolane (1.1moles), 83.4 g. of hydroxylamine hydrochloride (1.2 moles), 117.8 g. ofpotassium acetate (1.2. moles) and 1:1 ethanol-water (1.0 liter) isheated at reflux for 6 hours, then cooled in a freezer overnight. Whitecrystals of 2-formyl-2-methyl-1,3-dithiolane oxime are collected byfiltration, washed with a cold solution of 1:1 ethanol-water (200 m1.)and dried in vacuo, M.P. 104-1065 C.

Analysis.-Calculated for C H NOS (percent): C, 36.8; H, 5.6; N, 8.6.Found (percent): C, 37.0; H, 5.5; N, 8.3.

Using the general method described, the following oxime intermediates ofthe present invention are prepared from the compounds described above inExample 6.

2-formyl2-methylcyclohexano-1,3-dithiolane oxime,2-formyl-2,4,6-trimethyl-1,3-dithiane oxime,2-formyl-2-methyl-l,3-dithiane oxime,2-formyl-2,4-dimethyl-l,3-dithiolane oxime,

2-acetyl-2-methyl-1,3-dithiolane oxime,2-acetyl-2,4-dimethyl-1,S-dithiolane oxime, and2-ethyl-2-propionyl-1,3-dithiolane oxime.

To a stirred, cold (0-5 C.) solution of 24 g. of N,N- dimethylaniline(0.2 mole) and 200 ml. of diethyl ether under a nitrogen atmosphere andprotected by a Dry Ice condenser is added by bubbling 22 g. of gaseousphosgene (0.22 mole). As the solution becomes cloudy, 32.6 g. of2-formyl-2-rnethyl-1,3-dithiolane oxime (0.20 mole) dissolved in 200 ml.of diethyl ether is added dropwise while maintaining the reactiontemperature between 5 and +5 C. After the completion of the addition,the reaction is stirred for an additional hour at 0 C., then filtered.The colorless filtrate is reduced in volume in 240 ml.

To an ml. portion of this filtrate maintained at 0-5 C. is addeddropwise with stirring 9.0 g. of dimethylamine (0.20 mole). Thissolution is stirred for an additional hour at 0 C., and the white solidproduct removed by filtration. Recrystallization from n-hexane giveswhite crystals, M.P. 7576 C. The infrared spectrum of the compounds isconsistent with the structure of 2- formyl-2-methyl-l,3 dithiolane oximeN,N dimethylcarbamate.

' EXAMPLE 7 4-butyl-2-formyl-2-methyl-1,3-dithiolane oxime N,Ndimethylcarbamate Using the procedure of Example 6 and replacing 2-formyl-2-methyl-l,3-dithiolane with 4-butyl 2 formyl-2-methyl-1,3-dithiolane the desired product is obtained, as indicated byinfrared spectral analysis, as white crystals when recrystallized fromn-hexane.

EXAMPLE 8 2-formy1-2-methyl-1,3-dithiolane oxime N-methylcarbamate To astirred solution of 2-formyl-2-methyl-l,3-ditl1iolane oxime (81.6 g.,0.50 mole), triethylamine (1.0 ml.) and acetone (50 ml.) is added 30.8g. of methyl isocyanate (0.54 mole) in 50 ml. of acetone. This reactionmixture is heated at reflux temperature for 12 hours, cooled andfiltered. The volume of the solution is reduced to about 250 ml. byevaporation under vacuum. The product is obtained as a white solid andrecrystallized from acetone, M.P. 122-124 C. The infrared spectrum isconsistent with the assigned structure.

Analysis.--Calculated for C H N O S (percent): C, 38.2; H, 5.5. Found(percent): C, 38.0; H, 5.4.

Using the procedure of Example 8 the products of the following table areobtained using commercially available isocyanates as reactants. Theoximes may be prepared as in Example 6.

TABLE II Reactants Example N0. Oxime Isoeyanate Product 92-formyl-2metl1yl-1,B-dithiolane oxirne Ethyl isooyanato 2-ti%rrIriyi-z2 ;niigggi jl-l,3-dithiolane oxirne N-ethyloarbamate' ..don-Butylisoeyanate 2-fonnyl-2 -methyl l, -dithiolane oximeN-n-butylcarbamate, M.P. 6770 C. 11 .d0 Allyllsocyanate2-flsrmfiyg2mgthyl-l,Z-dithiolane oxime N-allylcarbamate,

'. 3-54 C. 12 2-floirgrgylb2-methyl-l,B-Iiithiane oxirne, M.P. 145-Methyl isocyanate 2-i\%rrI1 1yl-2-m ethyl-1,3-dithiane oximeN-methylcarbamate,

l .96-99 C. 13 2-iormyl-2A-dimethyl-1,3-dithiolane oxime,M.P. Methylisocyanate 2-forrnyl-2,4-dirnethyl-1, i-dithiolane oxirne N-rnethylcar-6$6o o. v ban1ate,M.P.737fiC. 14 2-formyl-2,4,6-tr1methyl-1,3-d1th1aneoxirne Methyl isocyanate 2-fgrmyl-2A,(Mrimethyl-l,3-dithiane oximeN-methylcaramate M.P. 4550 C. 152-formyl-2-methyleyclohexano-1,B-dithiolane Methyl isocyanatc-2-fonnyl-2-methylcyelohexano-1, i-dithiolane oxirne N- oxune.methylcarbamate, M.P. 132-134 C. 16 2-formyl-2-methyl-1,3-d1th1olaneoxirne t-Butyllsocyanate 2-t0rmyl-2methyl-1,3-dithiolane oximeN-t-butylearbamate, M.P. 8486 C. 17-..2-iormyl-2,5-dimethylbenzo-1,3-dithiolane oxirne. Methyl isoeyanate2-fonnyl-2,5-dimethylbenzo-l,3-dithi0lane oxime N-methylcarbamate, M.P.125-127 C. 18 2-formyl-2-methyl-4-phenyl-1,3-dithiolane oxime Methylisocyanate 2-iormyl-2methyl-4-phenyl-1,3-dithiolane oxirneN-methylcarbamate, M.P. 129-132" C. 19 2-formyl-2A-dimethyl-l,3-dith1aneoxnne Methyl lsoeyanate 2-formyl-2,4-dimethyl-1,3-dithiane oxirneN-rnethylcarbamate, M.P. IDS-107 C. 204-ethyl-2-formyl-2-methyl-1,3-dith1olaneox1me... Methyl isoeyanate2-ethyl-2-tormyl-2-methyl-1,3-dithiolane oxime N-methylcarbamate. 212-acetyl-2-methyl-1,S-dithiolane oxirne Methyl isoeyanate2-aeotyl-2-methyl-1,3-dithiolaneoxirne N-methylcarbamate,

M.P. 107-109 C. 22 2-acetyl-2,4-dimethyl-1,3-dithiolane oxime Methylisocyanate 2-acetyl-2,4-dimethyl-1,B-dithiolane oxirneN-methylcarbamate, M.P. 89-92 0 EXAMPLE 232-formyI-2-methyl-1,3-dithiolane oxime N-rnethylcarbamateS,S'-bisdioxide To a stirred, cold (0-5 C.) solution of 2-formyl-2-methyl-1,3-dithiolane oxirne N-methylcarbamate (4.4 g., 0.02 mole) inglacial acetic acid (75 ml.) is added dropwise 30 percent hydrogenperoxide solution (18.1 g., 0.16 mole). The solution is then heated toreflux for 2.5 hours. Next, 75 ml. of water is added, and the solutionis cooled slowly. White crystals separate and are collected byfiltration, M.P. 155 C. (dec.). The infrared spectrum is consistent withthe assigned structure.

EXAMPLE 24 2-formyl-2-methyl-1,3-dithiolane oxirne N-methylcarbamateS-oxide To a cold (05 C.) solution of 2-formyl-2-methyl- 1,3-dithiolaneoxirne N-methylcarbamate (4.4 g., 0.02 mole) in methane (100 ml.) isadded sodium metaperiodate (4.3 g., 0.02 mole) in water (50 ml.).External cooling is necessary to maintain the temperature at 05 C. Themixture is stirred cold for 4 hours, then allowed to warm to roomtemperature, and the white solid is removed by filtration. The filtrateis reduced in volume in vacuo to afford an oil which slowly solidifies.Recrystallization from 1:1 ethyl acetate: benzene gives beige crystals,M.P. 96-97 C. (dec.). The infrared spectrum of this compound isconsistent with the assigned structure.

EXAMPLE 25 2-formyl-2-methyl-1,3-dithiolane oxime N-methylcarbamateS,S'-dioxide To a stirred, cold (O -5 C.) solution of 2-formyl-2methyl-1,3-dithiolane oxime N-methylcarbamate (4.4 g., 20 mmole) inmethanol (150 ml.) is added dropwise over fifteen minutes a solution ofsodium metaperiodate (9.0 g., 42 mmoles) in water (100 1111.). A whiteprecipitate forms. The mixture is stirred cold (5-10 C.) for 45 minutesand filtered. The filtrate is evaporated in vacuo, removing the solvent.The residue is extracted three times with chloroform (50 ml. portions),the extracts are dried over magnesium sulfate, and the chloroformremoved in vacuo. Diethyl ether is added to the residue, then removed invacuo. Chloroform and hexane are added to the residue and the mixture isheated. The product, 2- formyl-Z-methyl-1,3-dithiolane oxirneN-methylcarbamate S,S'-dioxide, M.P. 126 C. (dec.), a tan solid, isremoved by filtration. Cooling the filtrate gives a second crop ofproduct.

Analysis.Calculated for C H N O S (percent): C, 33.3; H, 4.8; N, 11.1.Found (percent): C, 33.0; H, 4.8; N, 11.0.

The carbamoyloxime derivatives of the invention are tested fornematocidal activity by a standard test method using roots of tomatoplants infested with nematodes (Meloidogyne incognz'ta, var. acrita).They are tested for acaricidal activity by a standard test method usingcotton plants infested with T etranychus telarium and for theirinsecticidal activity using houseflies (Musca domestica) and mosquitolarvae (Aedes aegypti).

The following compounds were found to have a particularly high degree ofactivity as nematocides, acaricides or insecticides:

2-formyl--2-methyl-1,3-dithiolane oxirne N-methylcarbamate,

2-formyl-2-methy1-1,3-dithiane oxirne N-methylcarbamate,

2-formyl-2,4-dirnethyl-l,3-dithiolane oxirne N-methylcarbamate.

While all of the carbamyloxime compounds falling within the scope of thepresent invention as described in the general formula set forthhereinabove exhibit some nematicidal or insecticidal activity, it is tobe understood that some are more effective than others. The abovelistedcompounds are examples of preferred embodiments which exhibit highactivity, particularly as nematocides.

The compounds contemplated in this invention may be applied asinsecticides, acaricides and nematocides according to methods known tothose skilled in the art. Pesticidal compositions containing. thecompounds as the active toxicant will usually comprise a carrier ordiluent, either liquid or solid.

Liquid concentrates may be prepared by dissolving one of these compoundswith a solvent such as acetone or xylene and dispersing the toxicants inwater with the aid of suitable surface active agents, i.e. dispersingand emulsifying agents.

The choice of dispersing and emulsifying agent and the amount employedis dictated by the nature of the composition and the ability of theagent to facilitate the dispersion of the toxicant. Generally, it isdesirable to use as little of the agent as is possible, consistent withthe desired dispersion of the toxicant in the spray so that rain doesnot re-emulsify the toxicant after it is applied to the plant and washit off the plant. Nonionic, anionic or cationic surface active agentsmay be employed, for example, the condensation products of alkyleneoxides with phenol and organic acids, alkyl aryl sulfonates, complexether alcohols, quaternary ammonium compounds, and the like.

In the preparation of wettable powder or dust or granulatedcompositions, the active ingredient is dispersed in and on anappropriately divided solid carrier such as clay, talc, bentonite,diatomaceous earth, charcoal, corn cob granules, fullers earth, and thelike. In the formulation of the wettable powders the aforementionedsurface active agents as well as lign-osulfonates can be included.

The required amount of the toxicants contemplated herein may be appliedper acre treated in from 1 to 200 gallons or more of water as diluent orin from about 5 to 500 pounds of inert solid carrier or diluent. Theconcentration in the liquid concentrate will usually vary from about 5to 30 percent by weight, and in the solid formulations from about 2 toabout 80 percent by weight. The formulations are applied in amountswhich contain from about one-fourth to 15 pounds of active toxicant peracre.

The pesticides contemplated herein prevent attack by insects, mites andnematodes upon plants or other material to which the pesticides areapplied, and they have high residual toxicity. With respect to plantsthey have a high margin of safety in that when used in suflicient amountto kill or repel the insects, they do not burn or injure the plant. Thetoxicants are sufliciently chemically inert that they are compatiblewith substantially any other constituents of the spray schedule, andthey may be used in the soil, upon the seeds or the roots of plantswithout injuring either the seeds or roots of plants, yet by imbibitionor root uptake they may kill the pests feeding thereon. Furthermore,their properties are such that they are not unacceptably hazardous tothe user.

Some of the novel oximes of this invention have central nervous systemdepressant activity such as muscle relaxation and sedation.

What is claimed is:

1. A method for controlling insects or nematodes which comprisesapplying to the plants, or to the soil in which they are growing, aninsecticidally or nema- 10 tocidally effective amount of a compoundhaving the formula wherein A and A are independently selected from thegroup consisting of thio, sulfinyl and sulfonyl linkages, R R and R areindependently selected from the group consisting of lower alkyl andlower alkenyl, or R and R taken together from an alkylene or alkenylenegroup having up to 12 carbon atoms, 2 to 5 carbon atoms of which form achain linking the sulfur atoms, -R.; is hydrogen or lower alkyl, and Rand R are independently selected from the group consisting of hydrogenand alkyl, cycloaliphatic, alkoxy and alkenyl radicals having up to 10carbon atoms, and only one of R and R may be hydrogen.

2. The method according to claim 1, wherein the compound is 2formyl-Z-methyl-1,3-dithiolane oxime N- methylcarbamate.

3. The method according to claim 1, wherein the compound is 2formyl-2,4-dimethyl-1,3-dithiolarie oxime N-methylcarbamate.

4. The method according to claim 1, wherein the compound is2-formyl-2-methyl-1,3-dithiane oxime N-methylcarbamate.

References Cited UNITED STATES PATENTS 3,459,866 8/1969 Buchanan 424-327JEROM E D. GOLDBERG, Primary Examiner A. JAY ROBINSON, AssistantExaminer US. Cl. X.R. 424-327 UNHED STATES PATENT CFFEUE, QERHNQMEE CF@Qiihiifi'iififi Patent No. 3,72 ,77 v u Date -March 12 1072 lnventofls)Tomas L. Fridinger and Edward L. Mutsch It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

, Column 2, line20, for "forml" read; formyl-- Column 2, line 41, for"-4,5-di" read -4,6di

Column 3, line 29, after "like" insert and others such as diethyl ether,ethyl propyl ether and the like-- Column 5, line 22, for "out" read--ous-- Column 7, line &5, for "methane" read ---methanol-- Signed andsealed this 25th day of Decemher 19 73.

(SEAL) Attest: I

EDWARD M. FLEQYCHERJR. RENE D. TEG'IMEYER Attesting Officer ActingCommissioner of Patents l FORM POI-150 (10-69, US COMM-DC 6O376-P69 u.s.oovikrmem PRINTING orncs: 1959 o-aeG -au

